The invention relates to a gearshift device, especially in a motor vehicle, for shifting the speeds of a transmission. A gearshift lever pivotable in two planes carries a sphere for cooperation with a ball joint cup. The gear shift lever has a stop or detent mechanism which cooperates with complementary fixed position in the vicinity of the cup. The gearshift lever is constrained to move in two planes with the pivot angle being limited in each plane.
In a gearshift device disclosed in DE-PS [German Patent] No. 24 60 769, the detents or stops defining the angle of traverse in one plane are fastened on the lower end of the gearshift lever. These stops on the gearshift lever operate in conjunction with counter-stops provided in a shift-lever cover. As a result, when the gearshift lever pivots in the other plane, that is, when the transmission is shifted, the detents pivot along a circular path. Should a large transverse force be exerted during shifting, this could result in a certain tightness, along with wear between the detents. In addition, great care must be exercised in adjusting the pivot angle in one plane of the gearshift lever (preselection plane) relative to the shift rod connected to the gearing, because of the separation of the stops in space from the center of the ball joint sphere and accordingly the bearing bracket.
Consequently, the object of the invention is to develop a switchgear of its class that under all conditions is smooth-running, more wear-resistant, and simpler from the viewpoint of adjustment of the gearshift lever pivot angle.
This object is achieved with the characteristics of the invention described herein. In the invention, the movable stops on the gearshift lever and the fixed stops are thus so positioned in the area of the ball joint sphere that they roll over each other when the gearshift lever pivots in one plane (the shift plane). This means that only very slight friction occurs during such pivoting. A smooth-running, wear-minimized gearshift device is accordingly obtained. In addition, the adjustability of the pivot angle is improved as a result of positioning the stops in the immediate vicinity of the ball joint sphere, because it can be ascertained immediately by visual inspection of the stops whether the pivot angle of the shift lever more or less coincides with the torsion angle of the shift rod provided by the design.
More specifically, the stops mechanism includes a shackle surrounding the ball joint sphere at a distance through an angle of about 180.degree.. The shackle has a shell-like configuration with rounded elements at its ends and is secured in the vicinity of the ball joint sphere. This results in a reliably operating, technologically advantageous design where the ball joint sphere may be made of a strong, wear-resistant plastic material.
The fixed stops may be made up of elastic cushion plates, ones of plastic, for example, so that simplicity of manufacture is accompanied by elimination of the noise of impact occurring when the gearshift lever is pivoted. The cushion plates may be fastened to the adjusting plate by means of a clip connection, by fitting into retaining tabs formed on the adjusting plate, or by cementing.
The adjustability of the gearshift device in the stop plane (preselection plane) can be further improved at low cost. A base plate cooperates with an adjusting plate of the bearing-bracket to permit adjustment in one pivot plane. The base plate has a curved portion whose center of curvature is coextensive with that of the sphere. This permits adjustment of the pivot angle relative to the base plate by means of displacement about the axis of curvature. In operation, after the fastener has been loosened, the adjusting plate together with the shift lever can be pivoted, thus making it especially simple to establish the pivot angle to be set relative to the shift rod. The process is one in which the gearshift lever is first displaced as far as possible to one of the end stops of the pivot angle and is then pivoted in the other direction for purposes of adjustment until both a stop on the shift rod from the direction of the transmission and a stop on the gearshift lever side between the gearshift lever and the adjusting plate is reached. If the adjusting plate is fastened in this position, it is easy to make certain that the pivot angle of the gearshift lever has been set properly in the stop plane for operation relative to the torsion angle of the shift rod or relative to a base plate. The base plate may be either a section of the bottom plate of the vehicle or a separate base plate to be fastened on the bottom plate.
The above is a brief discussion of some deficiencies of the prior art and features of the invention which overcome these deficiencies.
An embodiment of the invention is discussed in detail in what follows. The schematic drawing shows in